Driving force control device for right and left wheel independent drive type vehicle

Abstract

A left electric motor for driving a left wheel and a right electric motor for driving a right wheel paired with the left wheel are provided, and a center of gravity position of the right and left wheel independent drive type vehicle is estimated, and a correction torque for canceling a yaw moment generated in accordance with a difference between the estimated center of gravity position of the right and left wheel independent drive type vehicle and a predetermined center of gravity position determined in advance is added to an output torque of the left electric motor and the right electric motor.

What is claimed is: 
     
         1 . A driving force control device for a right and left wheel independent drive type vehicle, the driving force control device comprising:
 a right electric motor that drives a right wheel, and a left electric motor that drives a left wheel paired with the right wheel; and   a controller that controls the right electric motor and the left electric motor, wherein the controller includes   a center-of-gravity estimation unit that estimates a center-of-gravity position of the right and left wheel independent drive type vehicle, and   a torque correction unit that adds correction torque for canceling a yaw moment to output torque of the right electric motor and the left electric motor, the yaw moment being generated according to a difference between the estimated center-of-gravity position of the right and left wheel independent drive type vehicle estimated by the center-of-gravity estimation unit and a predetermined center-of-gravity position determined in advance.   
     
     
         2 . The driving force control device according to  claim 1 , further comprising:
 a plurality of seats on which an occupant is to be seated; and   a plurality of seating sensors provided for each of the seats to detect that the occupant is seated, wherein the center-of-gravity estimation unit estimates the center-of-gravity position of the right and left wheel independent drive type vehicle based on a position of the seating sensor that detects that the occupant is seated.   
     
     
         3 . The driving force control device according to  claim 1 , further comprising:
 a plurality of suspensions that reciprocates in an up-down direction of the right and left wheel independent drive type vehicle to suppress vibration of each of the wheels in the up-down direction; and   a stroke sensor provided for each of the suspensions to detect a displacement amount of the suspension, wherein the center-of-gravity estimation unit estimates the center-of-gravity position of the right and left wheel independent drive type vehicle based on the displacement amount of the suspensions detected by the stroke sensor.   
     
     
         4 . The driving force control device according to  claim 1 , wherein the torque correction unit increases torque of one of the right electric motor and the left electric motor that is coupled to one of the right wheel and the left wheel on a side closer to the estimated center-of-gravity position estimated by the center-of-gravity estimation unit than the predetermined center-of-gravity position, and reduces torque of another of the right electric motor and the left electric motor. 
     
     
         5 . The driving force control device according to  claim 1 , wherein the center-of-gravity estimation unit estimates the center-of-gravity position of the right and left wheel independent drive type vehicle when the right and left wheel independent drive type vehicle is stopped or during straight travel in which a steering angle of the right and left wheel independent drive type vehicle is within a predetermined angle range.